Hive provides a number of useful user defined functions, but there is certainly room for more. HiveSwarm provides a collection of additional useful functions.
HiveSwarm has been tested with mrv1 on cdh4 and YARN on cdh5
Assuming you have Hadoop and Hive set up (along with your HADOOP_HOME and HIVE_HOME environment variables set correctly), run the following:
Download and install Maven http://maven.apache.org/download.cgi
git clone git://github.com/livingsocial/HiveSwarm.git
cd HiveSwarm
mvn package
You should now have a jar file in your target folder named HiveSwarm.jar.
Each of the following methods assumes you have first run the following in your hive session:
add jar /path/to/HiveSwarm.jar;
After you do that, you can create temporary functions as needed.
Run:
create temporary function max_date as 'com.livingsocial.hive.udf.MaxDate'
max_date takes any number of date ('2011-01-10') or date time ('2011-01-10 10:01:00') or null arguments. The max date among non-null arguments is returned.
Same as max_date, but returns min.
Run:
create temporary function intervals as 'com.livingsocial.hive.udtf.Intervals';
intervals takes a group column argument and an interval argument and returns a two column table with the intervals between the rows per group. The interval column can be a numerical or date/datetime (string) column.
Run:
create temporary function smin as 'com.livingsocial.hive.udf.SMin';
smin and smax act just like min and max but treat string columns like timestamps.
Same as regular Hive like but is case irrespective (just like MySQL's like). Use is like:
create temporary function ilike as 'com.livingsocial.hive.udf.ILike';
select city_name, count from city_counts where ilike(city_name, "%baltimore%");
Table generating function that returns up to count rows per group column of the group and value columns.
create temporary function first_n as 'com.livingsocial.hive.udtf.FirstN';
select first_n(person_id, value, 20) as (one, two) from person_values;
This will output the first 20 rows (by person_id) of (person_id, value).
Same as regular Hive unix_timestamp but can handle "yyyy-MM-dd HH:mm:ss" as well as "yyyy-MM-dd". Use is like:
create temporary function unix_liberal_timestamp as 'com.livingsocial.hive.udf.UnixLiberalTimestamp';
select city_name, unix_liberal_timestsamp(created_at) from cities;
Get first index of string needle in string haystack (optionally, starting search from startIndex). Returns -1 if not found.
create temporary function index_of as 'com.livingsocial.hive.udf.IndexOf';
select email from users where index_of('@', email) > -1;
Returns true if needle (primitive) is in haystack (array of primitives) and if needle is not null. Returns false otherwise.
create temporary function in_array as 'com.livingsocial.hive.udf.InArray';
select in_array(user_id, array(1,2,3,4)) from users;
Get day of week (as integer) from date (of format "yyyy-mm-dd"). Sunday is 1, Monday 2, etc.
create temporary function dayofweek as 'com.livingsocial.hive.udf.DayOfWeek';
select dayofweek(to_date(created_at)) from src;
Get representations of bits in a bitfield (it's like the bin UDF and a long case statement - hence, bin_case). If long represents a (big endian) bit field, bin_case will generate a single column table with a row for each positive bit containing the corresponding value in names. For instance, here are some examples:
create temporary function bin_case as 'com.livingsocial.hive.udtf.BinCase';
select bin_case(1, array("foo", "bar", "baz")) as c from source;
> foo
select bin_case(2, array("foo", "bar", "baz")) as c from source;
> bar
select bin_case(3, array("foo", "bar", "baz")) as c from source;
> foo
> bar
select bin_case(4, array("foo", "bar", "baz")) as c from source;
> baz
select bin_case(5, array("foo", "bar", "baz")) as c from source;
> foo
> baz
select bin_case(7, array("foo", "bar", "baz")) as c from source;
> foo
> bar
> baz
...
AES decrypt the given string (which should be Base32 hex encoded) with the given key.
create temporary function aes_decrypt as 'com.livingsocial.hive.udf.AESDecrypt';
select aes_decrypt(encrypted_data, "textkey") from secure_storage;
This will require downloading this file from Sun and installing to /usr/java/jdk1.6.0_22/jre/lib/security (due to cryptographic export controls).
gps_distance_from(latitude1 double, longitude1 double, latitude2 double, longitude2 double [, Text options])
Calculate the distance between two gps coordinates, return result in miles (default). Options accepts a parameter of 'km' - returns result in km
create temporary function gps_distance_from as 'com.livingsocial.hive.udf.gpsDistanceFrom'
hive -e "select gps_distance_from(38, -97, 37.33181, -122.02955) from test_coordinates"
> 1365.5982379566033
hive -e "select gps_distance_from(38, -97, 37.33181, -122.02955, 'km') from test_coordinates"
> 2197.717330666032
Coordinates are entered as doubles, and a double is returned. If any of the latitude or longitude values are passed in as null, null is returned
Return the index of an element greater than or equal to all of the other elements. In case of equality earlier elements will be preferred.
create temporary function index_of_max_elem as 'com.livingsocial.hive.udf.IndexOfMaxElem';
select index_of_max_elem(array(3,5,9,2)) from some_table;
> 2
Parses a user agent string into something a little more legible. By default (without the options field entered), returns a json parameter with all parsed data.
Accepts any of the following entered as a string, as user options
os, os_family, os_major, os_minor, ua, ua_family, ua_major, ua_minor, device
os and ua will return json, with _family, _major and _minor returned as well; other options will return a string.
Note: the underlying parser library is somewhat tuned to LivingSocial's interests; It includes some email clients, and reports AOL windows as AOL (as opposed to MSIE). This library builds off of http://github.com/p5k6/ua-parser. Tobie's ua-parser can be dropped in if needed/desired (http://github.com/tobie/ua-parser)
create temporary function user_agent_parser as 'com.livingsocial.hive.udf.UserAgentParser';
select user_agent_parser(user_agent) from some_table;
> {user_agent: {family: "Firefox", major: "12", minor: "0", patch: null}, os: {family: "Windows", major: "7", minor: null, patch: null, patch_minor: null}, device: {family: null}}
select user_agent_parser(user_agent, 'os') from some_table;
> {family: "Windows", major: "7", minor: null, patch: null, patch_minor: null}
select user_agent_parser(user_agent, 'os_family') from some_table;
> "Windows"
Returns the current date in the form 'YYYY-MM-DD'
create temporary function curdate as 'com.livingsocial.hive.udf.Curdate';
select curdate() from some_table;
> 2012-12-26
Returns the current date and time in the form 'YYYY-MM-DD HH:mm:ss'
create temporary function curdatetime as 'com.livingsocial.hive.udf.CurDateTime';
select curdatetime() from some_table;
> 2012-12-26 13:26:25
Returns the year of an ISO week number. Same as unix date's %G. Used in conjunction with week_of_year. Ensures that each week/year combination has 7 days. Accepts input in the form 'YYYY-MM-DD' and 'YYYY-MM-DD HH:mm:ss'.
create temporary function iso_year_of_week as 'com.livingsocial.hive.udf.IsoYearWeek';
select iso_year_of_week('2012-01-01') from some_table;
> 2011
Returns an md5 hash of the string passed in Fork of datamine's md5 hash function; originally found at https://gist.github.com/1050002
create temporary function md5 as 'com.livingsocial.hive.udf.Md5';
select md5('test data') from some_table;
> eb733a00c0c9d336e65691a37ab54293
Returns the sha1 hash of the string passed in
create temporary function sha1 as 'com.livingsocial.hive.udf.Sha1';
select sha1('test data') from some_table;
> f48dd853820860816c75d54d0f584dc863327a7c
Returns a deterministic 'random' number based on the sha1 has of the passed in string and salt. This is intended to be used in place of many rand() uses. It has the benefit of being repeatable, consistent, and easily implementable by any system. An id for a row is required as the first input. An optional string salt can be passed in as the second argument. A third string can be passed in and the output will change to a string output showing internal debugging information.
This implementation can be used in other systems so the same samples can be shared by only sharing the logic and the salt. The pseudo-code logic for this is:
to_hash = something_to_hash + some_salt
sha1_hash = sha1(to_hash.to_utf8_bytes())
hex = sha1.substring(0,14)
return Long.parse_hex(hex) / (2^56)
Examples:
-- simple example to extract a 10% sample
select * from some_table where ls_hash(id, 'my salt') < 0.1;
-- Label 2 non-overlapping groups A and B with 50% in each
select if(ls_hash(id, 'some other salt')<=0.5, 'A', 'B') as group_label, id, name from some_table;
Returns a ranking of each row within a group of rows
Forked from Edward Capriolo's branch - https://github.com/edwardcapriolo/hive-rank/. Wanted to fit the function into LivingSocial's Hive UDF implementation. original copyright: "Copyright 2012 m6d Media6degrees"
create temporary function p_rank as 'com.livingsocial.hive.udf.Rank';
SELECT
category,country,product,sales,rank
FROM (
SELECT
category,country,product,sales,
p_rank(category, country) rank
FROM (
SELECT
category,country,product,
sales
FROM p_rank_demo
DISTRIBUTE BY
category,country
SORT BY
category,country,sales desc) t1) t2
> movies gb Star Wars iv 300 1
> movies gb Star Wars iii 200 2
> movies gb spiderman 150 3
> movies gb Goldfinger 100 4
> movies us Star Wars v 300 1
> movies us Star Wars iii 200 2
> movies us Star Wars iv 150 3
> movies us casablanca 100 4
Concatenates the elements of the array separated by the delimiter. Note: This duplicates the functionality of the built in concat_ws UDF, but handles any primitive types in the array instead of only strings.
create temporary function concat_array as 'com.livingsocial.hive.udf.ConcatArray';
-- Generate a comma separated list of products in a category
select category, concat_array(',', collect_set(product)) from products group by category;
returns the lowest value amongst several columns
nulls are considered to be the lowest value (which fits how the oracle function least() works).
Inspired by NexR's 'greatest' function (https://github.com/nexr/hive-udf)
create temporary function least as 'com.livingsocial.hive.udf.GenericUDFLeast';
select least('2013-05-24','2012-05-09','1004-67-83') from test limit 1
> 1004-67-83
select least(0,1,3,4,65) from test limit 1
> 0
returns the lowest value amongst several columns, excluding nulls.
create temporary function least_non_null as 'com.livingsocial.hive.udf.GenericUDFLeastNonNull';
select least('2013-05-24','2012-05-09','1004-67-83',null) from test limit 1
> 1004-67-83
select least(0,1,3,4,65) from test limit 1
> 0
z_test(double controlAvg, double controlStddev, long controlSize, double treatmentAvg, double treatmentStddev, long treatmentSize)
Performs a Z-test to compare the mean of the control group vs. the mean of the treatment group. Returns the two sided p-value for the given Z-test.
create temporary function z_test as 'com.livingsocial.hive.udf.ZTest';
SELECT z_test(avg(if(control=1, revenue, 0)), stddev_pop(if(control=1, revenue, 0)), sum(if(control=1, 1, 0)),
avg(if(control=0, revenue, 0)), stddev_pop(if(control=0, revenue, 0)), sum(if(control=0, 1, 0)))
FROM revenue_table;
Alternate form:
z_test(critical_value) -- This skips the rest and just does a normal dist lookup"
Strips HTML tags and elements from a string using the jsoup parser.
create temporary function strip_html as 'com.livingsocial.hive.udf.StripHTML';
select strip_html("<strong>Hello World!</strong><br />") from test limit 1;
> Hello World!
Tokenizes a string of natural language text into an array of stemmed lower-case words.
Common english stop-words such as "a" and "the" will be removed.
Stemming is performed by the KStemFilter from Apache Lucene, which is less aggressive than the Porter stemmer, and results in stems that are still dictionary words.
This function also strips out HTML and converts accented characters to their ASCII equivalents.
create temporary function tokenize as 'com.livingsocial.hive.udf.Tokenize';
select tokenize("The horses jumped with élan") from test limit 1;
> [horse, jump, elan]
This will run a javax.script based UDF that can be defined as a literal script in the UDF call or as a file in HDFS.
Function descriptions in the script:
- evaluate receives all the extra script_arguments passed in the scriptedUDF call and returns an object adhering to the defined return_type
Language is the javax.script engine name. Additional languages can be added by adding the jar implementing the scripting engine ('add jar groovy-all.jar;' or similar) Return_type is a hive style data definition ('string', 'bigint', 'array<map<string,string>>', ...)
Example:
create temporary function scriptedUDF as 'com.livingsocial.hive.udf.ScriptedUDF';
-- Gather complex data combining groups and individual rows without joins
select person_id, purchase_data['time'], purchase_data['diff'],
purchase_data['product'], purchase_data['purchase_count'] as pc,
purchase_data['blah']
from (
select person_id, scriptedUDF('
require "json"
def evaluate(data)
# This gathers all the data about purchases by person in one place so complex infromation can be gathered while avoiding complex joins
# Note: In order for this to work all the data passed into scriptedUDF for a row needs to fit into memory
tmp = [] # convert things over to a ruby array
tmp.concat(data)
tmp.sort_by! { |a| a.get("time") } # for the time differences
last=0
tmp.map{ |row|
# Compute the time difference between purchases and add the total purchase count per person
t = row["time"]
# The parts that would be much more difficult to generate with SQL
row["diff"] = t - last
row["purchase_count"] = tmp.length
row["first_purchase"] = tmp[0]["time"]
row["last_purchase"] = tmp[-1]["time"]
# This shows that built-in libraries are available
row["blah"] = JSON.generate({"id" => row["id"]})
last = t
row
}
end', 'ruby', 'array<map<string,string>>',
-- gather all the data about purchases by people so it can all be passed into the evaluate function
bh_collect(map( -- Note, bh_collect is from Klouts Brickhouse and allows collecting any type, see https://github.com/klout/brickhouse/
'time', unix_liberal_timestamp(purchase_time),
'product', product_id)) ) as all_data
from purchases
group by person_id
) foo
-- explode the data back out so it is available in flattened form
lateral view explode(all_data) bar as purchase_data
Alternate syntax:
create temporary function scriptedUDF as 'com.livingsocial.hive.udf.ScriptedUDF';
SELECT scriptedUDF('/my_scripts/reusable.rb', 'ruby', 'map<string,int>', val1, val2) FROM src_table;
This will load the script from the location in HDFS and will invoke the evaluate function. This function needs to return a map of strings keys and int values.
Any bugs / request can be submited via tickets on Github.